gdb/language.h

   1 /* Source-language-related definitions for GDB.
   2
   3    Copyright (C) 1991-2015 Free Software Foundation, Inc.
   4
   5    Contributed by the Department of Computer Science at the State University
   6    of New York at Buffalo.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #if !defined (LANGUAGE_H)
  24 #define LANGUAGE_H 1
  25
  26 #include "symtab.h"
  27
  28 /* Forward decls for prototypes.  */
  29 struct value;
  30 struct objfile;
  31 struct frame_info;
  32 struct expression;
  33 struct ui_file;
  34 struct value_print_options;
  35 struct type_print_options;
  36 struct lang_varobj_ops;
  37 struct parser_state;
  38 struct compile_instance;
  39
  40 #define MAX_FORTRAN_DIMS  7     /* Maximum number of F77 array dims.  */
  41
  42 /* range_mode ==
  43    range_mode_auto:   range_check set automatically to default of language.
  44    range_mode_manual: range_check set manually by user.  */
  45
  46 extern enum range_mode
  47   {
  48     range_mode_auto, range_mode_manual
  49   }
  50 range_mode;
  51
  52 /* range_check ==
  53    range_check_on:    Ranges are checked in GDB expressions, producing errors.
  54    range_check_warn:  Ranges are checked, producing warnings.
  55    range_check_off:   Ranges are not checked in GDB expressions.  */
  56
  57 extern enum range_check
  58   {
  59     range_check_off, range_check_warn, range_check_on
  60   }
  61 range_check;
  62
  63 /* case_mode ==
  64    case_mode_auto:   case_sensitivity set upon selection of scope.
  65    case_mode_manual: case_sensitivity set only by user.  */
  66
  67 extern enum case_mode
  68   {
  69     case_mode_auto, case_mode_manual
  70   }
  71 case_mode;
  72
  73 /* array_ordering ==
  74    array_row_major:     Arrays are in row major order.
  75    array_column_major:  Arrays are in column major order.  */
  76
  77 extern enum array_ordering
  78   {
  79     array_row_major, array_column_major
  80   }
  81 array_ordering;
  82
  83
  84 /* case_sensitivity ==
  85    case_sensitive_on:   Case sensitivity in name matching is used.
  86    case_sensitive_off:  Case sensitivity in name matching is not used.  */
  87
  88 extern enum case_sensitivity
  89   {
  90     case_sensitive_on, case_sensitive_off
  91   }
  92 case_sensitivity;
  93
  94
  95 /* macro_expansion ==
  96    macro_expansion_no:  No macro expansion is available.
  97    macro_expansion_c:   C-like macro expansion is available.  */
  98
  99 enum macro_expansion
 100   {
 101     macro_expansion_no, macro_expansion_c
 102   };
 103
 104 \f
 105 /* Per architecture (OS/ABI) language information.  */
 106
 107 struct language_arch_info
 108 {
 109   /* Its primitive types.  This is a vector ended by a NULL pointer.
 110      These types can be specified by name in parsing types in
 111      expressions, regardless of whether the program being debugged
 112      actually defines such a type.  */
 113   struct type **primitive_type_vector;
 114
 115   /* Symbol wrappers around primitive_type_vector, so that the symbol lookup
 116      machinery can return them.  */
 117   struct symbol **primitive_type_symbols;
 118
 119   /* Type of elements of strings.  */
 120   struct type *string_char_type;
 121
 122   /* Symbol name of type to use as boolean type, if defined.  */
 123   const char *bool_type_symbol;
 124   /* Otherwise, this is the default boolean builtin type.  */
 125   struct type *bool_type_default;
 126 };
 127
 128 /* A pointer to a function expected to return nonzero if
 129    SYMBOL_SEARCH_NAME matches the given LOOKUP_NAME.
 130
 131    SYMBOL_SEARCH_NAME should be a symbol's "search" name.
 132    LOOKUP_NAME should be the name of an entity after it has been
 133    transformed for lookup.  */
 134
 135 typedef int (*symbol_name_cmp_ftype) (const char *symbol_search_name,
 136                                           const char *lookup_name);
 137
 138 /* Structure tying together assorted information about a language.  */
 139
 140 struct language_defn
 141   {
 142     /* Name of the language.  */
 143
 144     const char *la_name;
 145
 146     /* Natural or official name of the language.  */
 147
 148     const char *la_natural_name;
 149
 150     /* its symtab language-enum (defs.h).  */
 151
 152     enum language la_language;
 153
 154     /* Default range checking.  */
 155
 156     enum range_check la_range_check;
 157
 158     /* Default case sensitivity.  */
 159     enum case_sensitivity la_case_sensitivity;
 160
 161     /* Multi-dimensional array ordering.  */
 162     enum array_ordering la_array_ordering;
 163
 164     /* Style of macro expansion, if any, supported by this language.  */
 165     enum macro_expansion la_macro_expansion;
 166
 167     /* Definitions related to expression printing, prefixifying, and
 168        dumping.  */
 169
 170     const struct exp_descriptor *la_exp_desc;
 171
 172     /* Parser function.  */
 173
 174     int (*la_parser) (struct parser_state *);
 175
 176     /* Parser error function.  */
 177
 178     void (*la_error) (char *);
 179
 180     /* Given an expression *EXPP created by prefixifying the result of
 181        la_parser, perform any remaining processing necessary to complete
 182        its translation.  *EXPP may change; la_post_parser is responsible
 183        for releasing its previous contents, if necessary.  If
 184        VOID_CONTEXT_P, then no value is expected from the expression.  */
 185
 186     void (*la_post_parser) (struct expression ** expp, int void_context_p);
 187
 188     void (*la_printchar) (int ch, struct type *chtype,
 189                           struct ui_file * stream);
 190
 191     void (*la_printstr) (struct ui_file * stream, struct type *elttype,
 192                          const gdb_byte *string, unsigned int length,
 193                          const char *encoding, int force_ellipses,
 194                          const struct value_print_options *);
 195
 196     void (*la_emitchar) (int ch, struct type *chtype,
 197                          struct ui_file * stream, int quoter);
 198
 199     /* Print a type using syntax appropriate for this language.  */
 200
 201     void (*la_print_type) (struct type *, const char *, struct ui_file *, int,
 202                            int, const struct type_print_options *);
 203
 204     /* Print a typedef using syntax appropriate for this language.
 205        TYPE is the underlying type.  NEW_SYMBOL is the symbol naming
 206        the type.  STREAM is the output stream on which to print.  */
 207
 208     void (*la_print_typedef) (struct type *type, struct symbol *new_symbol,
 209                               struct ui_file *stream);
 210
 211     /* Print a value using syntax appropriate for this language.
 212
 213        TYPE is the type of the sub-object to be printed.
 214
 215        CONTENTS holds the bits of the value.  This holds the entire
 216        enclosing object.
 217
 218        EMBEDDED_OFFSET is the offset into the outermost object of the
 219        sub-object represented by TYPE.  This is the object which this
 220        call should print.  Note that the enclosing type is not
 221        available.
 222
 223        ADDRESS is the address in the inferior of the enclosing object.
 224
 225        STREAM is the stream on which the value is to be printed.
 226
 227        RECURSE is the recursion depth.  It is zero-based.
 228
 229        OPTIONS are the formatting options to be used when
 230        printing.  */
 231
 232     void (*la_val_print) (struct type *type,
 233                           const gdb_byte *contents,
 234                           int embedded_offset, CORE_ADDR address,
 235                           struct ui_file *stream, int recurse,
 236                           const struct value *val,
 237                           const struct value_print_options *options);
 238
 239     /* Print a top-level value using syntax appropriate for this language.  */
 240
 241     void (*la_value_print) (struct value *, struct ui_file *,
 242                             const struct value_print_options *);
 243
 244     /* Given a symbol VAR, and a stack frame id FRAME, read the value
 245        of the variable an return (pointer to a) struct value containing
 246        the value.
 247
 248        Throw an error if the variable cannot be found.  */
 249
 250     struct value *(*la_read_var_value) (struct symbol *var,
 251                                         struct frame_info *frame);
 252
 253     /* PC is possibly an unknown languages trampoline.
 254        If that PC falls in a trampoline belonging to this language,
 255        return the address of the first pc in the real function, or 0
 256        if it isn't a language tramp for this language.  */
 257     CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR);
 258
 259     /* Now come some hooks for lookup_symbol.  */
 260
 261     /* If this is non-NULL, specifies the name that of the implicit
 262        local variable that refers to the current object instance.  */
 263
 264     char *la_name_of_this;
 265
 266     /* This is a function that lookup_symbol will call when it gets to
 267        the part of symbol lookup where C looks up static and global
 268        variables.  */
 269
 270     struct symbol *(*la_lookup_symbol_nonlocal) (const struct language_defn *,
 271                                                  const char *,
 272                                                  const struct block *,
 273                                                  const domain_enum);
 274
 275     /* Find the definition of the type with the given name.  */
 276     struct type *(*la_lookup_transparent_type) (const char *);
 277
 278     /* Return demangled language symbol, or NULL.  */
 279     char *(*la_demangle) (const char *mangled, int options);
 280
 281     /* Return class name of a mangled method name or NULL.  */
 282     char *(*la_class_name_from_physname) (const char *physname);
 283
 284     /* Table for printing expressions.  */
 285
 286     const struct op_print *la_op_print_tab;
 287
 288     /* Zero if the language has first-class arrays.  True if there are no
 289        array values, and array objects decay to pointers, as in C.  */
 290
 291     char c_style_arrays;
 292
 293     /* Index to use for extracting the first element of a string.  */
 294     char string_lower_bound;
 295
 296     /* The list of characters forming word boundaries.  */
 297     char *(*la_word_break_characters) (void);
 298
 299     /* Should return a vector of all symbols which are possible
 300        completions for TEXT.  WORD is the entire command on which the
 301        completion is being made.  If CODE is TYPE_CODE_UNDEF, then all
 302        symbols should be examined; otherwise, only STRUCT_DOMAIN
 303        symbols whose type has a code of CODE should be matched.  */
 304     VEC (char_ptr) *(*la_make_symbol_completion_list) (const char *text,
 305                                                        const char *word,
 306                                                        enum type_code code);
 307
 308     /* The per-architecture (OS/ABI) language information.  */
 309     void (*la_language_arch_info) (struct gdbarch *,
 310                                    struct language_arch_info *);
 311
 312     /* Print the index of an element of an array.  */
 313     void (*la_print_array_index) (struct value *index_value,
 314                                   struct ui_file *stream,
 315                                   const struct value_print_options *options);
 316
 317     /* Return non-zero if TYPE should be passed (and returned) by
 318        reference at the language level.  */
 319     int (*la_pass_by_reference) (struct type *type);
 320
 321     /* Obtain a string from the inferior, storing it in a newly allocated
 322        buffer in BUFFER, which should be freed by the caller.  If the
 323        in- and out-parameter *LENGTH is specified at -1, the string is
 324        read until a null character of the appropriate width is found -
 325        otherwise the string is read to the length of characters specified.
 326        On completion, *LENGTH will hold the size of the string in characters.
 327        If a *LENGTH of -1 was specified it will count only actual
 328        characters, excluding any eventual terminating null character.
 329        Otherwise *LENGTH will include all characters - including any nulls.
 330        CHARSET will hold the encoding used in the string.  */
 331     void (*la_get_string) (struct value *value, gdb_byte **buffer, int *length,
 332                            struct type **chartype, const char **charset);
 333
 334     /* Return a pointer to the function that should be used to match
 335        a symbol name against LOOKUP_NAME. This is mostly for languages
 336        such as Ada where the matching algorithm depends on LOOKUP_NAME.
 337
 338        This field may be NULL, in which case strcmp_iw will be used
 339        to perform the matching.  */
 340     symbol_name_cmp_ftype (*la_get_symbol_name_cmp) (const char *lookup_name);
 341
 342     /* Find all symbols in the current program space matching NAME in
 343        DOMAIN, according to this language's rules.
 344
 345        The search is done in BLOCK only.
 346        The caller is responsible for iterating up through superblocks
 347        if desired.
 348
 349        For each one, call CALLBACK with the symbol and the DATA
 350        argument.  If CALLBACK returns zero, the iteration ends at that
 351        point.
 352
 353        This field may not be NULL.  If the language does not need any
 354        special processing here, 'iterate_over_symbols' should be
 355        used as the definition.  */
 356     void (*la_iterate_over_symbols) (const struct block *block,
 357                                      const char *name,
 358                                      domain_enum domain,
 359                                      symbol_found_callback_ftype *callback,
 360                                      void *data);
 361
 362     /* Various operations on varobj.  */
 363     const struct lang_varobj_ops *la_varobj_ops;
 364
 365     /* If this language allows compilation from the gdb command line,
 366        this method should be non-NULL.  When called it should return
 367        an instance of struct gcc_context appropriate to the language.
 368        When defined this method must never return NULL; instead it
 369        should throw an exception on failure.  The returned compiler
 370        instance is owned by its caller and must be deallocated by
 371        calling its 'destroy' method.  */
 372
 373     struct compile_instance *(*la_get_compile_instance) (void);
 374
 375     /* This method must be defined if 'la_get_gcc_context' is defined.
 376        If 'la_get_gcc_context' is not defined, then this method is
 377        ignored.
 378
 379        This takes the user-supplied text and returns a newly malloc'd
 380        bit of code to compile.  The caller owns the result.
 381
 382        INST is the compiler instance being used.
 383        INPUT is the user's input text.
 384        GDBARCH is the architecture to use.
 385        EXPR_BLOCK is the block in which the expression is being
 386        parsed.
 387        EXPR_PC is the PC at which the expression is being parsed.  */
 388
 389     char *(*la_compute_program) (struct compile_instance *inst,
 390                                  const char *input,
 391                                  struct gdbarch *gdbarch,
 392                                  const struct block *expr_block,
 393                                  CORE_ADDR expr_pc);
 394
 395     /* Add fields above this point, so the magic number is always last.  */
 396     /* Magic number for compat checking.  */
 397
 398     long la_magic;
 399
 400   };
 401
 402 #define LANG_MAGIC      910823L
 403
 404 /* Pointer to the language_defn for our current language.  This pointer
 405    always points to *some* valid struct; it can be used without checking
 406    it for validity.
 407
 408    The current language affects expression parsing and evaluation
 409    (FIXME: it might be cleaner to make the evaluation-related stuff
 410    separate exp_opcodes for each different set of semantics.  We
 411    should at least think this through more clearly with respect to
 412    what happens if the language is changed between parsing and
 413    evaluation) and printing of things like types and arrays.  It does
 414    *not* affect symbol-reading-- each source file in a symbol-file has
 415    its own language and we should keep track of that regardless of the
 416    language when symbols are read.  If we want some manual setting for
 417    the language of symbol files (e.g. detecting when ".c" files are
 418    C++), it should be a separate setting from the current_language.  */
 419
 420 extern const struct language_defn *current_language;
 421
 422 /* Pointer to the language_defn expected by the user, e.g. the language
 423    of main(), or the language we last mentioned in a message, or C.  */
 424
 425 extern const struct language_defn *expected_language;
 426
 427 /* language_mode ==
 428    language_mode_auto:   current_language automatically set upon selection
 429    of scope (e.g. stack frame)
 430    language_mode_manual: current_language set only by user.  */
 431
 432 extern enum language_mode
 433   {
 434     language_mode_auto, language_mode_manual
 435   }
 436 language_mode;
 437
 438 struct type *language_bool_type (const struct language_defn *l,
 439                                  struct gdbarch *gdbarch);
 440
 441 struct type *language_string_char_type (const struct language_defn *l,
 442                                         struct gdbarch *gdbarch);
 443
 444 /* Look up type NAME in language L, and return its definition for architecture
 445    GDBARCH.  Returns NULL if not found.  */
 446
 447 struct type *language_lookup_primitive_type (const struct language_defn *l,
 448                                              struct gdbarch *gdbarch,
 449                                              const char *name);
 450
 451 /* Wrapper around language_lookup_primitive_type to return the
 452    corresponding symbol.  */
 453
 454 struct symbol *
 455   language_lookup_primitive_type_as_symbol (const struct language_defn *l,
 456                                             struct gdbarch *gdbarch,
 457                                             const char *name);
 458
 459 \f
 460 /* These macros define the behaviour of the expression
 461    evaluator.  */
 462
 463 /* Should we range check values against the domain of their type?  */
 464 #define RANGE_CHECK (range_check != range_check_off)
 465
 466 /* "cast" really means conversion.  */
 467 /* FIXME -- should be a setting in language_defn.  */
 468 #define CAST_IS_CONVERSION(LANG) ((LANG)->la_language == language_c  || \
 469                                   (LANG)->la_language == language_cplus || \
 470                                   (LANG)->la_language == language_objc)
 471
 472 extern void language_info (int);
 473
 474 extern enum language set_language (enum language);
 475 \f
 476
 477 /* This page contains functions that return things that are
 478    specific to languages.  Each of these functions is based on
 479    the current setting of working_lang, which the user sets
 480    with the "set language" command.  */
 481
 482 #define LA_PRINT_TYPE(type,varstring,stream,show,level,flags)           \
 483   (current_language->la_print_type(type,varstring,stream,show,level,flags))
 484
 485 #define LA_PRINT_TYPEDEF(type,new_symbol,stream) \
 486   (current_language->la_print_typedef(type,new_symbol,stream))
 487
 488 #define LA_VAL_PRINT(type,valaddr,offset,addr,stream,val,recurse,options) \
 489   (current_language->la_val_print(type,valaddr,offset,addr,stream, \
 490                                   val,recurse,options))
 491 #define LA_VALUE_PRINT(val,stream,options) \
 492   (current_language->la_value_print(val,stream,options))
 493
 494 #define LA_PRINT_CHAR(ch, type, stream) \
 495   (current_language->la_printchar(ch, type, stream))
 496 #define LA_PRINT_STRING(stream, elttype, string, length, encoding, force_ellipses, options) \
 497   (current_language->la_printstr(stream, elttype, string, length, \
 498                                  encoding, force_ellipses,options))
 499 #define LA_EMIT_CHAR(ch, type, stream, quoter) \
 500   (current_language->la_emitchar(ch, type, stream, quoter))
 501 #define LA_GET_STRING(value, buffer, length, chartype, encoding) \
 502   (current_language->la_get_string(value, buffer, length, chartype, encoding))
 503
 504 #define LA_PRINT_ARRAY_INDEX(index_value, stream, options) \
 505   (current_language->la_print_array_index(index_value, stream, options))
 506
 507 #define LA_ITERATE_OVER_SYMBOLS(BLOCK, NAME, DOMAIN, CALLBACK, DATA) \
 508   (current_language->la_iterate_over_symbols (BLOCK, NAME, DOMAIN, CALLBACK, \
 509                                               DATA))
 510
 511 /* Test a character to decide whether it can be printed in literal form
 512    or needs to be printed in another representation.  For example,
 513    in C the literal form of the character with octal value 141 is 'a'
 514    and the "other representation" is '\141'.  The "other representation"
 515    is program language dependent.  */
 516
 517 #define PRINT_LITERAL_FORM(c)           \
 518   ((c) >= 0x20                          \
 519    && ((c) < 0x7F || (c) >= 0xA0)       \
 520    && (!sevenbit_strings || (c) < 0x80))
 521
 522 /* Type predicates */
 523
 524 extern int pointer_type (struct type *);
 525
 526 /* Error messages */
 527
 528 extern void range_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 529
 530 /* Data:  Does this value represent "truth" to the current language?  */
 531
 532 extern int value_true (struct value *);
 533
 534 /* Misc:  The string representing a particular enum language.  */
 535
 536 extern enum language language_enum (char *str);
 537
 538 extern const struct language_defn *language_def (enum language);
 539
 540 extern const char *language_str (enum language);
 541
 542 /* Add a language to the set known by GDB (at initialization time).  */
 543
 544 extern void add_language (const struct language_defn *);
 545
 546 extern enum language get_frame_language (void); /* In stack.c */
 547
 548 /* Check for a language-specific trampoline.  */
 549
 550 extern CORE_ADDR skip_language_trampoline (struct frame_info *, CORE_ADDR pc);
 551
 552 /* Return demangled language symbol, or NULL.  */
 553 extern char *language_demangle (const struct language_defn *current_language,
 554                                 const char *mangled, int options);
 555
 556 /* Return class name from physname, or NULL.  */
 557 extern char *language_class_name_from_physname (const struct language_defn *,
 558                                                 const char *physname);
 559
 560 /* Splitting strings into words.  */
 561 extern char *default_word_break_characters (void);
 562
 563 /* Print the index of an array element using the C99 syntax.  */
 564 extern void default_print_array_index (struct value *index_value,
 565                                        struct ui_file *stream,
 566                                        const struct value_print_options *options);
 567
 568 /* Return non-zero if TYPE should be passed (and returned) by
 569    reference at the language level.  */
 570 int language_pass_by_reference (struct type *type);
 571
 572 /* Return zero; by default, types are passed by value at the language
 573    level.  The target ABI may pass or return some structs by reference
 574    independent of this.  */
 575 int default_pass_by_reference (struct type *type);
 576
 577 /* The default implementation of la_print_typedef.  */
 578 void default_print_typedef (struct type *type, struct symbol *new_symbol,
 579                             struct ui_file *stream);
 580
 581 void default_get_string (struct value *value, gdb_byte **buffer, int *length,
 582                          struct type **char_type, const char **charset);
 583
 584 void c_get_string (struct value *value, gdb_byte **buffer, int *length,
 585                    struct type **char_type, const char **charset);
 586
 587 #endif /* defined (LANGUAGE_H) */